How electricity works
How electricity works ?
Table of content
Introduction of how electricity works
Today the leading edge of technology powered by electricity. Our cell phones, lights, laptops, air conditioners and what is in your mind powered by electricity. I mean your brain synapses. It is great. But what exactly is that? And how electricity works?
Electricity is a natural interacting between atoms. Yes, for understanding what is electricity and how electricity works we must to take a look at atoms. You may know there are more than a hundred forms of atoms that have different characteristics. Copper, Hydrogen, Oxygen and Carbon are examples of atoms. You can find them all on the periodic table.
Atoms are made of Electrons, Protons and Neutrons. A group of electrons are orbiting around the nucleus which is made of Protons and Neutrons. The chemical characteristics of each atom is depends on number of protons in nucleus. And the electrical characteristics? Yes, it depends on the number of electrons. The orbital model (Bohr model) of each atom in balanced state have equal number of electrons and protons. But electrons which are orbiting around the nucleus in some cases can escape. With enough energy (ionization energy) the electrons which are on the outer orbit (valence electrons) can become free.
The image shows an atom which is composed of Neutrons, Protons and Electrons. The number of Protons and Electrons are equal in balanced state.
Another physical property of matter that is necessary to understanding electricity is electrical charge. For understanding this property we must again take a look at atom. The electrons carry negative electric charge and the positive electric charge is carried by protons. Both carry the same amount of charge. Neutrons don’t have net charge (neutral).
As mentioned above just electrons can transfer between atoms (free electrons) and the number of protons of an atom which indicate the chemical characteristics is fixed. When the atom is in balanced state (the number of electrons and protons are equal) there aren’t electric charge (neutral). When the number of protons are less than electrons atom has negative electric charge and when the number of electrons are more than protons atom has negative electric charge.
The SI unit of electric charge is C (the Coulomb). Coulomb’s law indicates there is a force that operates between charges. It says that the opposite type charges attracted together and the same types repel each other. This is called electrostatic force. The amount of electrostatic force depends on the electric charges distance. So the greater force depends on how the charges are close together.
As we know just electrons can move between atoms (free electrons). Each electron has a negative charge, so they are our charge carrier. The force to release an electron depends on number of atom valence electrons. The fewer ones needs less energy or force (attracting with positive charge or pushing with another negative charge) to release. Metal elements usually have less valence electrons. Thus the charge flow indicates the electrical conductivity of matter which is using for classification of elements as a metal, a nonmetal, or a semiconductor. Matters with high electrical conductivity are called conductors. These types of material (conductors) are the main part of anything that are used for transferring electricity like wires. Low conductivity matters are called Insulators. Insulators are used for preventing the flow of electrons. It is important to know that the insulators can withstand a certain amount of force and more force can ionize the insulator and cause it to become a conductor. Air, glass, rubber and plastic are popular insulators.
Metal has a high electrical conductivity
Metallic elements (for example copper atom) in the solid state generally have high electrical conductivity. A nonmetal has more possible valence electrons than a metal, so a metal has a small ionization energy in compare with a nonmetal. For example copper has just one valence electron on the outer orbit which requires relatively little energy to be ejected from the outer ring. The motion of a free electron in order to correlate with another nearby constitute an electrical current. Gold, Silver, Copper and Aluminum are examples of good conductors.
Copper atom and copper wire
Copper like Aluminum is one of the most used materials to build conductors like wires, PCBs and other electrical equipment. Gold and silver are more expensive and are used in the special cases. Copper has 29 Protons and 29 Electrons. One electron exists on the outer orbit. So with a small ionization energy it can be released. Copper conductivity is more than Aluminum, but it’s more expensive. So in the cheap wires and electronic devices you can find Aluminum. However in some cases like transmission lines we have to use Aluminum, not only it is economical but also for its chemical characteristics.
Now consider a copper wire. There are a huge amount of copper atoms in the wire space, so with a little force free electron of an atom can go through this space. Our free electron eventually finds another atom to latch on, but its negative charge ejects the atom’s valence electron from its orbit. So there is a new free electron in the space and this chain effect can continue until the fore is exist. This continuous chain effect creating a flow of electrons in the wire and called electrical current or in short current.
When there are two groups of opposite charges and they don’t link together with a conductor we have static electricity. The charges are connected together with insulator. So until the two groups find a way (conductor) to balance each other. If there isn’t enough Insulator layer between two groups or charge of them are so great, the attraction force between two groups may ionize the insulator and make them touch and then you can see a static discharge occurs. Static discharge may be harmful and destruct the insulator depends on the charges rate and insulator ingredient. Transferring electrons needs energy and depends on how harder is that we need more energy.
The biggest static electricity discharge in the nature is lightning. It’s amazing and we can see big discharges between clouds or clouds and the earth. In this case the insulator is air. When the charges are so great they can ionize the air between each other and in a blink of eye a big discharge occurs. Lots of our devices based on static electricity. The most important one is capacitor. Capacitor is a static energy storage.
When charges are constantly flow though high conductivity materials we can have a constant energy transfer between two places. Today the electricity is the most important shape of energy in our planet. Because invented devices are highly based on electricity. For example your mobile phone or your laptop.
Conclusion of how electricity works
So in the end we can say that how electricity works? It works by electron flow. Yes, all things about electricity is summarized in the behavior of electrons. Electricity laws justifies the behavior of electrons and by discovery of these rules we can use them as energy carriers to meet our needs (communication, lighting, transferring, Heating and cooling and etc.)